What is B2M Protein
Proteins are the workhorses of the human body and play key roles in various biological processes. Among these proteins, beta-2 microglobulin (B2M) is a multifaceted protein that plays an important role in various biological processes.
B2M is a small protein found on the surface of almost all nucleated cells in the human body. B2M, encoded by the B2M gene located on chromosome 15, is a key component of the major histocompatibility complex class I (MHC-I) system, a group of cell surface molecules critical for immune surveillance.
Figure 1. 3D crystal structures of B2M and MHC class I complex. (Wang, C., et al. 2022)The Function of B2M Protein
Immune System Support: At the core of B2M's functions lies its role in the immune system. B2M, in complex with the heavy chain of MHC-I proteins, facilitates antigen presentation. Antigens are peptides derived from intracellular pathogens or cancer cells and presented on the cell surface by antigen-presenting cells (APCs). These antigens are recognized by cytotoxic T lymphocytes (CTL) and natural killer (NK) cells, initiating an immune response against the threat.
Cell Homeostasis: B2M is also integral for regulating the turnover of cell surface proteins, including receptors and adhesion molecules. This process ensures that cells can respond appropriately to their microenvironment and maintain normal function.
B2M-Related Diseases
Dialysis-Related Amyloidosis: In patients with end-stage renal disease (ESRD) undergoing chronic dialysis, inefficient clearance of B2M by the kidneys leads to its accumulation in the blood. This accumulation ultimately leads to the amyloid deposits in various tissues, causing joint pain, stiffness, and organ dysfunction.
Multiple Myeloma: Patients with multiple myeloma have elevated levels of B2M, and measuring B2M in the blood can serve as a prognostic marker for the disease. Elevated B2M levels are associated with more aggressive disease and poorer prognosis.
HIV Infection: B2M has been implicated in HIV infection and pathogenesis. The virus interacts with MHC-I molecules, causing B2M degradation and shedding from the cell surface, allowing the virus to evade recognition by CTLs and persist in the host.
Autoimmune Diseases: Autoimmune diseases, such as systemic lupus erythematosus (SLE) and rheumatoid arthritis, involve an abnormal immune response that results in the production of autoantibodies. B2M plays a role in these diseases by presenting self-antigens on MHC-I, triggering immune responses against the body's own tissues.
B2M Related Signaling Pathways
MHC-I Antigen Presentation Pathway: B2M is a component of the MHC-I antigen presentation pathway. The pathway begins with intracellular processing of antigens, which are loaded onto MHC-I molecules together with B2M. The MHC-I/B2M/antigen complex is transported to the cell surface to initiate an immune response against infected or malignant cells.
Endocytic Pathway: B2M is also involved in the endocytic pathway, controlling the internalization and degradation of cell surface proteins. This pathway is critical for regulating cell surface receptor expression and maintaining cellular homeostasis.
NK Cell Activation: Natural killer (NK) cells play a critical role in detecting and eliminating infected or transformed cells. B2M affects the recognition of target cells by NK cells, and theabsence of MHC-I on the cell surface makes virally infected or malignant cells more susceptible to NK cell-mediated cytotoxicity.
Applications of B2M in Biomedical Research
The unique properties and functions of B2M open the door to numerous applications in biomedical research.
Biomarker for Disease: Monitoring B2M levels in the blood can serve as valuable biomarkers for a variety of diseases, including multiple myeloma, providing insights into disease progression and treatment response.
Transplantation Medicine: B2M plays a crucial role in organ transplantation, where the compatibility of donor and recipient MHC-I molecules, including B2M, determines the success of the transplant. Understanding the role of B2M is critical to improving transplant.
Drug Development: B2M is a potential target for drug development, especially in situations where its function is dysregulated, such as in autoimmune diseases or cancer. Modulating B2M expression and function may enhance immune responses against cancer cells or suppress autoimmunity.
Immunotherapy: Immunotherapies, including checkpoint inhibitors,are revolutionizing cancer treatment. The role of B2M in antigen presentation and immune responses is critical to developing effective immunotherapies and restoring the immune system's ability to recognize and target cancer cells.
Alzheimer's Disease Research: Recent studies have linked B2M to Alzheimer's disease. B2M is found in amyloid plaques, a hallmark of Alzheimer's disease pathology. Studying the role of B2M in Alzheimer's disease may provide insights into potential therapeutic targets for this neurodegenerative disease.
B2M is a complex protein with diverse functions, ranging from supporting immune responses and maintaining cellular homeostasis to involvement in diseases such as dialysis-associated amyloidosis, multiple myeloma, and autoimmune disorders. Its role in signaling pathways, particularly the MHC-I antigen presentation pathway, is critical to our understanding of immune responses and potential therapeutic intervention.
B2M's applications in biomedical research, including its role as a biomarker and its importance in transplantation medicine, drug development, immunotherapy and Alzheimer's disease research, demonstrate the enormous potential of this protein to advance healthcare and improve the quality of life of individuals around the world.
Recommended Products for B2M Protein
| Cat.# | Species | Product name | Source (Host) | Tag |
|---|---|---|---|---|
| FCGRT & B2M-11B | Bovine | Active Recombinant Bovine FCGRT & B2M Protein, His-Avi-tagged, Biotinylated | HEK293 | His/Avi |
| B2M-2101C | Cynomolgus | Recombinant Cynomolgus B2M protein, His-tagged | HEK293 | His |
| FCGRT & B2M-12F | Feline | Active Recombinant Feline FCGRT&B2M protein, His-Avi-tagged, Biotinylated | HEK293 | His-Avi |
| FCGRT & B2M-1928H | Human | Active Recombinant Human FCGRT & B2M Protein, His-Avi/Strep II-tagged, Biotinylated | HEK293 | His/Avi/StrepII |
| B2M-2783H | Human | Recombinant Human B2M protein, His-tagged | E.coli | His |
| B2M-10092H | Human | Recombinant Human B2M, GST-tagged | E.coli | GST |
| B2M-3237H | Human | Recombinant Human B2M, His tagged | Human Cell | His |
| B2M-26758TH | Human | Recombinant Human B2M, His-tagged | E.coli | His |
| B2M-938M | Mouse | Recombinant Mouse B2M Protein, His-tagged | HEK293 | His |
| B2M-1111R | Rat | Recombinant Rat B2M protein, His-tagged | HEK293 | His |
Reference:
- Wang, C., et al. The immune-related role of beta-2-microglobulin in melanoma. Front. Oncol. 2022, 12: 944722.
